Laundering composition and process



vlfi'phosphate itself or from other sources such as alkaline solutions employed in washing. Alu- 15 I Patented July 13, 1937 v UNITED STATES PATENT. OFFICE LAUNDERING COMPOSITION AND. PROCESS Ralph 11.1mm, Mount- Lebanon, Pa., assignor to Bali Laborateries, Inc., Pittsburgh, Pa, a corporation of Pennsylvania I No Drawing. Application June 19, 1936,

. Serial No. 86,157

9 Claims. (Cl. 87-5) This invention relates to laundering, and more lutions employed for washing, the alkalinity particularly to preventing the deposition of causes the conversion of the iron into the ferric metals such as iron, aluminum or copper in the hydroxide which is insoluble and is entrained in goods during the laundering operation. It relates the fabrics, causing the familiar yellowing of more especially to the prevention of yellowing the fabrics. of the goods by iron compounds. The present in- Iron may also be introduced into the washing vention has been developed especially in connecoperations from other so 'rces such as iron in tion with the use of alkali-metal metaphosphates the water supply or iron may be carried in the in laundering in order to overcome any tendency goods themselves. Soluble iron salts from any 10 to yellowing of the goods if the metaphosphateis source, when they encounter the high alkalinity l contaminated with iron. It is applicable, howof the wash water, are converted into the inever, irrespective of the source of contaminasoluble ironhydroxi'de which yellows the goods. .tion, that is, whether the contaminating iron, Aluminum and copper salts or soaps, ii presaluminum or. copperis derivedfrom the metaale'deposited in the the highly the, water employed in washing or because it minum maybe present in the water where alum is present in the goods themselves. or sodium aluminate'is used in treating the This application is a continuation-impart of water prior to the washing operation. Small my copending application Serial No. 685,743, amounts of aluminum may also'be dissolved by filed August 18, 1933. i the water where aluminum. apparatus is em- In my Reissue Patent No. 19,719, reissued Ocployed. Aluminum may also be carried into the tober 8, ,1935, I have described, among other wash water on the goods themselves. Aluminum, things, a process oflaundering goods using an if present, may form insoluble aluminum soaps, alkali-metal metaphosphate, preferably sodium by reaction withthe usual soaps employed in g7,- hexametaphosphate. Usually, a small amount washing in the presence of the highly alkaline of soda ash or bicarbonate of soda and soda ash, solution. These aluminum salts or soaps form or other alkali, is added to the sodium hexametaan objectionable deposit in the goods, entrapphosphate in order to.overcorne its slight acidity. ping So and Preventing thorough cleansing o V In carrying out the preferred washing procthe goods. i v 11'.) ess described in my patent, the goods are put into The water may be Contaminated With Small the laundry wheel and subjected to what .is amounts of copper due either to the corrosion of known as the break. The break consists in ,brass pipe or to the dissolving action of the preliminary subjecting the goods to lukewarm h y alkaline Wash Water on pp apparatus water containing sodium hexametaphosphate Where such metal is employ e copper may 3.; and perhaps asmall amount of soap or an addibe precipitated in the highly alkaline wash wational amount of alkali. The object of the break te as co ored deposits of hydoxide, silicate or is to loosen and remove some of the dirt before. basic carbonate, depending upon the particuthe goods are subjected to the washing cperalar alkali used in the laundering operation, these tion. colored deposits being entrained in' the goods. -10 After the break, the water is drained off and Although sodium hexametaphosphate will se-'- 40 hot water isrun into the laundry wheel, toque fi i i aluminum and pp in b e gether with soap and some sodium hexametameta-p p Complexes. in neutral y phosphate and also at times additional alkali, slightly alkaline solutions these metals are preand the goods are given the washing treatment cipitated in h y alkaline Solutions 'haVe 'After the washing is completed, the wash water found, however, that these metals may be kept 45 is drained off and the goods are rinsed, preferinsolution in inert colorless form in the alkaline ably with rinse water containing a small amount solutions encountered in laundering operations, of sodium hexametaphosphate. by the use of tartrates, oxalates'or citrates which Unless great care is taken in its preparation, will combinewith the metals to keep them in a sodium hexametaphosphate is likely to be consoluble colorless condition. Referring to the tar- 5() taminated with a few hundredths of 1% of the' trates by way of example, I may employ the 'iron compounds, probably iron phosphate. In the -alkali-metal tartrates, ammonium tartrates, or" alkaline solutions employed in the break and tartaric acid,iwhich may be considered as by}. i washing operations, this iron may be converted drogen tartratefand which when added lto. the into ferric hydroxide which is deposited in the alkaline solution forms the tartrate ,I ;:have goods, resulting in imparting a yellowish tinge found that the compounds having the formula to white goods. In neutral or'but slightly alka- R2C4H4Os, in which each R stands for a member line solutions, the iron is held in solution by the of the group consisting of hydrogen, ammonium hexamtaphospliate which forms-* a soluble iron and an alkali-metal, are suitable for this purpose. complex with it, but in the strongly alkaline so- Any of these tartrates may be used, such for ex- 60 ample as cream of tartar. I may use sodium tartrate, potassium tartrate, or the sodium-potassium tartrate, or the acid tartrates, or even. tartaric acid, so long as the: compound yields the tartaric-acid radical in soluble form and does not itself introduce discolorlng matter.

Likewise, the oxalates or citrates oi the alkalimetals or ammonium; or oxalic acid or citric acid may be used in place of the tartrates or tartaric, acid to prevent the deposition of iron, aluminum or copper in the goods in alkaline solution.

For the purpose of preventing the deposition of iron, aluminum or copper in alkaline solutions,

I use in conjunction with an alkali-metal hexametaphosphate, a. compound having the formula RxM in which each R stands for a member of the group consisting of hydrogen, ammonium and an alkali-metal, and in which the acid radical M is selected from the group of acids consisting of tartaric acid, oxalic acid or citric acid, and in which :i: is the valence of the radical M.

If the alkali-metal hexametaphosphate, such as sodium hexametaphosphate, employed is contaminated with a small amount of iron or other contaminating metal, enough of the tart-rate, oxalate or citrate is mixed with the metaphosphate to sequester the iron or other contaminating metal into the tartrate, oxalate or citrate molecule where it is kept in a soluble colorless formso that it is not deposited upon the goods.

For sodium hexametaphosphate contaminated with, say, about i of 1% or iron, I may use an amount of tartrate which corresponds to by weight of the metaphosphate used.

from the water or goods and will also vary according to the particular contaminating metal which it is desired to sequester and according to the particular agent used for this purpose.

By the use of the tartrates, oxalates or citrates, alkali-metal hexametaphosphates may be used which are not entirely freed from iron compounds or compounds of other contaminating metals in their manufacture. The term alkali-metal hexametaphosphate includes not-only sodium hexametaphosphate, but the hexametaphosphates of the other alkali-metals, such as potassium, ammonium, lithium, etc.

In general, the use of the tartrates, oxalates or citrates is applicable to various cleansing operations to which the goods are subjected in laundering, such as th break", the suds, and even the rinse. I

While I have specifically described the preierred procedure in carrying out my invention, it is to be understood that the invention is not so limited, but may be otherwise embodied and practiced within the scope of the following claims.

I claim:

1. A process of laundering goods in the presence'ofiron, aluminum or copper, which comprises immersing the goods in an alkaline solution containing an alkali-metal hexametaphosphate together with a water-soluble compound containing an acid radical of the group consisting of tartaric acid, oxalic acid and citric acid,

which prevents deposition of the metals in the goods by the alkaline water.

2. A process of laundering goods in the pres- This amount will vary naturally with the amount of iron present in the metaphosphate or derived added to alkaline ence of iron, aluminum or copper, which comprises: immersing the goods in an alkaline solution containing an alkali-metal hexametaphosphate: together with a water-soluble compound 'having: the formula RzM in which each R: stands for a. member of the group consisting of hydrogen, ammonium and an alkali-m'etal, and in which the acid radical M is selected from the group of acids consisting of tartaric acid, oxalic acid and citric acid, and in which a: is the valence of the radical M.

3. A process of laundering goods in the presence of iron, aluminum or copper, which comprises immersing the goods in an alkaline solution containing an alkali-metal hexametaphos- R2C4H4Os, in which each R stands for a member of the group consisting of hydrogen, ammonium and an alkali-metal.

5. A process of laundering goods in the presence of iron, aluminum or copper, whlch'comprises immersing the goods in an alkaline 'solution containing soap and an alkali-metal hexametaphosphate, and preventing the deposition of the metals in the goods by incorporating in the alkaline solution a compound having the formula R2C4H40s, in which each R stands for a phate together with a water-soluble compound containing the tartaric acid radical, which premember of the group consisting of hydrogen, am- I moniur'n and an alkali-metal.

6. As a washing composition, a mixture of an alkali-metal hexametaphosphate and a compound having the formula R2C4H406, in which each R stands for a member of the group consisting of hydrogen, ammonium and an alkalimetal, which compound prevents deposition of iron, aluminum and copper in the goods by alkaline water.

7. As a washing composition, a mixture of an alkali-metal hexametaphosphate and a watersoluble compound containing the tartaric acid radical, which compound prevents the deposition of iron, aluminum and copper in the goods by alkaline water.

8. A washing composition containing an alkali-metal hexametaphosphate and a water-solublecompound containing an acid radical of the group consisting of tartaric acid, oxalic acid and citric acid, which prevents deposition of iron, aluminum and copper when the composition is water.

. 9. A washing composition containing an alkali-metal hexametaphosphate and a water-s01- uble compound having the formula RrM, in which each R stands for a member of the group consisting of hydrogen, ammonium and an alkali-metal, and in which the acid radical M is selected from the group of acids consisting of tartaric acid, oxalicacid and citric acid, and in which a: is the valence of the radical M.

' RALPH E. HALL. 

